and especially in the southeast around the city a of mariupol. and there's some speculation as to why russia is doing this. one, it might be easier because it's closer to the russian border and could be that russia hopes to consolidate its gains there, hold territory so that if there are peace negotiations, it could present facts on the ground and try to hold on he areas which are very close to crimea. i've been told that the battle commander in the south are more effective than the commanders in the north. so, come of it may be depending on the qualifications and capabilities of the individual russian commander. as we know, widely reported there's been morale issues, supply chain issues and frostbite issues. so, individual leaders do matter. >> and briefly on the black sea port outside of mariupol, which was a key russian supply